高压下ZrB_2的结构和热力学性质的第一性原理计算

First-principles Calculations for the Structure and Thermodynamic Properties of ZrB_2 Compound under High Pressure

利用平面波赝势密度泛函理论计算了ZrB_2的基本参数,包括晶格常数、体弹模量、体弹模量对压强的一阶导数,同时通过准谐德拜模型研究了ZrB_2热力学性质,给出了不同压强和不同温度下的热容和德拜温度的计算值,发现热容随着压强增加而减小,德拜温度随压强增加而增加.

This paper uses the plane-wave pseudopotential density functional theory to calculate the equilibrium lattice parameters, including the lattice constant a and c, the bulk modulus B0 and the first order derivative of bulk modulus to the pressure. The thermodynamic properties of ZrB2 are obtained through the quasi-harmonic Debye model. It also calculates the heat capacities and the Debye temperatures at various temperatures and pressures. The results show that as the pressure increases, the heat capacity Cv decreases and the Debye temperature ΘD, increases.